AVNET Azure Sphere MT3620 Starter Kit - Review

Table of contents

RoadTest: AVNET Azure Sphere MT3620 Starter Kit

Author: sean_agilecadence

Creation date:

Evaluation Type: Development Boards & Tools

Did you receive all parts the manufacturer stated would be included in the package?: True

What other parts do you consider comparable to this product?: Seeed Sphere

What were the biggest problems encountered?: Please look under Problems Found below

Detailed Review:



For the Azure Sphere MT3620 RoadTest review I wanted to avoid the run of the mill apps that people typically do. We’ve all done Azure IoT consuming telemetry from various units (Azure Sphere, Pi, MX chips) at some point and had them feed a machine learning model, so where we produce a lot of solutions in IoT, so I wanted to evaluate the Avnet Sphere boards using the Mikroe Click boards in terms for potential future IoT solutions for our company.

To this end, I will be using the Heartrate4 Click board which gives the hearts average heart rate & blood oxygen level, have them upload into IoT and have the results announced verbally by our Misty the Robot we have evaluating for Misty Robotics.

What this review won’t do is cover existing ground on how to register your sphere board, how to set up an azure tenant, or deployment through feeds. All this information is easy to find, and Microsoft do a nice PDF that you can download. Avnet also do a pretty good installation guide for the Sphere board.




I’m a Microsoft Azure Technical Architect & Innovations Evangelist for AgileCadence. I have over 28years of software development experience, creating solutions for small businesses to large global brands, including selling various IP to major software companies in the process. But I’m not here to blow my own trumpet, I’m here to talk about the Avnet Sphere board.


Integrating the Azure Sphere with the Heartbeat HR4 Sensor


The road test board actually arrived a week after another one we wanted to use for a proof of concept so I had already had all the necessary training on how to setup Sphere, Tenants and claiming the devices.

What I really like about the Avnet board first is the simplicity of the plug’n’play sensor components without having to wire to wire them like other boards & sensors used in IoT development. Simply plug the sensor in and start coding. With a choice of over 600+ click boards from Mikroe electronics and a prototyping click board the possibilities are endless.

Integrating the HeartRate4 is simple. From starting the Sphere claim process to downloading the necessary libraries and getting a straight forward solution working in Visual Studio takes less than 30mins.

Upon finding the libraries for the HeartRate4 and the Avnet Demo code, and opening the demo solution. The only issue I had was that the references to the max30102.h and algorithm_by_rf.h were wrong, but being an experienced developer it was a simple case of refereeing the libraries wrong, so after reconfiguring and rebuilding, the solution soon started giving me my Heartrate and Blood Oxygen levels. The only way to check if the heart rate was accurate was to test this result against my iWatch at the same time and both results were consistent within +/- 1bpm. Impressive.

Integrating the Telemetry to Sphere & IoT/Central


As this is our second Avnet sphere board, we already had a preconfigured solution that hooked into our IoT Hub and Microsoft IoT Central application, it was relatively easy to re-use our Azure Connectivity class to send the telemetry to Azure.

Again, by re-using our Azure connectivity class it meant we was able to securely upload to Azure and get the results displayed in Central in near enough-real time.

Problems Found


Not a problem per se with the Heartrate4, but an observation that I made on our other Avnet board that is on 24/7 feeding my machine learning solution. I’ve noticed that after 4 days that unless the board is reset it will fail to send data starting with small gaps in time building up to hours, then days. The code checks out and wi-fi logging does show there were disconnections by the unit. So I can only assume that it may be a faulty unit. However the potentially faulty kid I might add was supplied from a different vendor.

Apart from the sample code having a couple of broken links to the header files, everything worked smoothly with no problems.

Evaluation & Summary


In terms of ease of use, connectivity and simplicity, the Avnet excels when compared to other sphere boards and other IoT solutions.

The main issue I have is that you can only have two Click board sensors installed at any one time along with a Grove. Yes, you can use a Mikroe Click board Prototyping board to use like a breadboard but then you’re into a world of pain when trying to use multiple sensors on breadboard through one Microbus connection.

If you could have 4 Click board expansion slots that would be better as the majority of our IoT solutions utilise more than 2 sensors. A competitor of Avnet in the sphere arena allows you to connect combine the four headers allowing you to use a Grove Shield which has building ADC and 6 grove connectors. If Avnet could have something like this then this would be an awesome board.

Because of the limited connectivity I feel that at present the Avnet board will become the go-to prototyping board for proof of concepts where the solutions use less than or equal to 3 sensors. To this, I can highly recommend using the Avnet board!

  •   I had similar hit or miss readings when I used Azure Sphere and the Heart Rate 4 for this project: Sensing the World: Sensing Myself

  • Hi Sean,


    I'm currently working with the HR4 and the Avnet Starter Kit.  I have the solution working but it's hit or miss getting good readings from the HR4.  Would you mind sharing your project?  I would like to compare the performance using your solution to my solution.





  •   wrote:


    Also if I had the time to spend writing an in-depth technical review then I would be distracted from doing my real job.


    So nothing personal DAB, but one doesn't have the time to sit and do a 10 page report.

    To be honest, it does look like a very cursory road test. In my opinion a short, basic road test is fine if that's what you said you'd do in your application. If you claimed that you had the time and that you'd be writing an in-depth technical review then it's not. Only you and Randall would know...

  • To be honest DAb, I don't claim.... I am... Check my bio on LinkedIn. No offense.

    Also if I had the time to spend writing an in-depth technical review then I would be distracted from doing my real job. Not being funny what is the point of producing the same old screen shots like everybody else? When we've all set up the sphere, etc.


    I don't make a number of claims, they are facts based on my personal experience of this board. I'm actually using the Seeed Sphere board production level with a grove board as our solutions use not only sensors, but LoRa too.


    So nothing personal DAB, but one doesn't have the time to sit and do a 10 page report. I'm outgoing, helpful and collaborative in nature and if anyone has questions I'm more than happy to help and lay the crumbs for themselves to discover the knowledge themselves instead of cutting and pasting other peoples solution.s


    So no offense taken.

  • If you are going to claim that you are an evangelist for this system, You need to provide a lot more data, tests and results to prove it.


    You make a number of claims about the benefits, so I want to see your testing and results.


    Nothing personal, but demonstrating the benefits and weaknesses of a product is one of the objectives of the road test process.



  • Assuming the use of I2C devices with different I2C addresses, could you not just use a Grove I2C hub to extend the number of devices?

  • Hi David,

    Indeed the HR4, I was dubious at first as the pins were bent. I also found for some bizarre reason that the board would only run in debug mode in a specific com port in VS2019. The Mikroelectronica sample code is ok.. ish. The names are the same as they are the header libraries that you must use to access the device functionality. If you like feel free to upload onto GitHub and i'll have a peek.

  • I'm also using the Heart Rate 4 sensor. How do you find it? I find that it's great when it gets a reading but it will only do that about 10% of the time using the mikroelectronica sample code. (By the filenames, it looks like you're using the same code.)